/* -*- coding: utf-8 -*-
 *
 * 1217.cc:  No.1217 せしすせそ - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

/* typedef */

/* global variables */

char s[32];

/* subroutines */

/* main */

int main() {
  scanf("%s", s);

  for (int i = 0; s[i]; i++)
    if (s[i] != 'a' + i) {
      printf("%cto%c\n", 'a' + i, s[i]);
      break;
    }
  return 0;
}